export default{
  namespaced:true,
  
  state:() => (
  {
    //存储购物车每个商品的信息对象
    // {id, name ,price,count,logo,state}
    cart:JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
  
  mutations:{
    addToCart(state, goods){
     const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
     // findresult可能为undefined 和 x
     if(!findResult){ //没找到同样的商品，要添加
       state.cart.push(goods)
     }else{
       findResult.goods_count++
     }
     this.commit('m_cart/saveToStorage')
    },
    // 本地存储
    saveToStorage(state){
      uni.setStorageSync('cart',JSON.stringify(state.cart))
    },
    // 更新购物车商品勾选状态
    updateGoodsState(state, goods){
     const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
     if(findResult){
       findResult.goods_state = goods.goods_state
       this.commit('m_cart/saveToStorage')
     }
    },
    // 更新商品的数量
    updateGoodsCount(state, goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if(findResult){
        findResult.goods_count = goods.goods_count
        this.commit('m_cart/saveToStorage')
      }
    },
    // 根据ID删除商品
    removeGoodsById(state, goods_id){
     state.cart = state.cart.filter(x => x.goods_id !== goods_id)
     this.commit('m_cart/saveToStorage')
    },
    // 更新全选按钮的状态
    updateAllGoodsState(state, newState){
      state.cart.forEach(x => x.goods_state = newState)
      this.commit('m_cart/saveToStorage')
    }
    
  },
  
  getters:{
    // 购物车所有商品总数量
    total(state){
      // let c = 0;
      // state.cart.forEach(goods => c += goods.goods_count)
      // return c
      return state.cart.reduce((total, item) => total += item.goods_count, 0)
    },
    // 购物车被选中的数量
    checkedCount(state){
     return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count, 0)
    },
    // 已勾选商品的总价格
    checkedGoodsAmount(state){
     return state.cart.filter(x => x.goods_state).reduce((totalAmount, x) => totalAmount += x.goods_count * x.goods_price, 0).toFixed(2)
    }
  }
  
}